PostV1InstancesPayinsCardPaymentSubmits a card payment for a payin on a specific instance using a single-use Collect.js payment token, cardholder name, billing address, and optional 3D Secure authentication data.
Submit Card Payment
| Name | Required | Description | Default |
|---|---|---|---|
| payin_id | Yes | ||
| instance_id | Yes | ||
| requestBody | Yes |
Changes observed during successful MCP inspections.
v1.9.3Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already disclose that this is a non-readonly, open-world, non-idempotent, non-destructive write operation. The description adds no behavioral context beyond that, such as the one-time nature of the payment token, 3DS requirements on production, or what happens on failed submission.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is only three words and is front-loaded, but it is under-specified rather than efficiently concise. It omits the context needed to understand the operation's scope and does not earn its place as a useful tool description.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
This is a complex payment submission tool with nested 3DS and billing data, no output schema, and multiple sibling payin tools. The description does not explain the workflow, required production 3DS behavior, or how this differs from other payin submission routes, leaving significant gaps.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is reported as 0%, so the description should compensate for undocumented parameters, but it says nothing about instance_id, payin_id, or requestBody. The nested schema does describe some request fields, which prevents this from being a 1, but the description itself adds no parameter meaning.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The phrase 'Submit Card Payment' gives a clear verb and resource, so the basic purpose is understandable. However, it essentially restates the tool title and does not distinguish this card-payment path from sibling payin submission tools such as PostV1InstancesPayinsEvm or the payin-quote tools.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
There is no guidance on when to use this tool versus alternatives, no prerequisites, and no mention of production 3DS requirements or token lifecycle. The POST name implies a write operation, but the description does not help the agent choose this tool correctly among the many payin-related siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.